—Must I go and repair our TV set this afternoon?

—No, you _______. I've repaired it.[ ]

A. mustn't

B. needn't

C. shouldn't

D. wouldn't

我们公司位于东莞长安，单位一员工不幸遭遇工伤事故。经劳动能力鉴定为工伤七级，但是我们对结论有异议。这种情况应该怎么处理？单位可以帮忙申请复查吗？